Preheat the oven to 400 F
Drizzle the squash with olive oil, I like to use a pastry brush to do this job. Season with salt and pepper.
Place it onto a baking sheet, open side down. Cooking spaghetti squash in the oven will give you the best carnalized flavor.
Place the spaghetti squash into the preheated oven onto the bottom rack, and allow it to bake for 40 minutes to an hour. The size of the squash will determine the cooking time.
After the 40 minutes have passed, take the pan out of the oven. Flip the squash open side up. Check for doneness by scraping the spaghetti squash with the end of a fork. If it feels too firm for your liking, flip it back open side down, and return it into the oven for a few more minutes.